The simmons sdxpress compact might be an option for you. They're only $250. I've never played one, nor am I a fan of electric drums, but in your situation these might be a good option. If not, guitar center has a 15 or 30 day return policy, depending on the item. Utilize it! LoL

Thanks dear , But I didn't like it : ( , It's small and sounds stupid comparing to KAT KT1,KT2
do you advise me with the Roland TD-4KP ???
Thanks